A completely new map rotation would be cool. No maps like granary, gullywash, badlands or snakewater. We would see new strategies and be even more excited to watch invite matches so that we can learn how to play the maps. This would also promote creativity among players of all levels.
I think we need to take a new approach in map design. If we can move away from last-choke-second-choke-mid-choke-second-choke-last, we could create new stages in the game outside of pushing/holding a choke or a control point.